I have a 2 in 1 under warranty and it gave me a BIOS based warning that it could no longer verify AC Adapter voltage and thus stopped charging.  I ran diagnostics and it said the same thing.

My wife also has a Dell and her adapter charges it fine so I am sure that's the issue.

Is this common to Dell?  I had an HP and had continual issues with the same thing, they replaced the on laptop power connection once, and the adapter three times.  I had hoped I had moved away from this by going to Dell and 5 months in its already started.  At least with the HP it would charge when asleep/off, this will not charge in any state from the current adapter.